Amnesty International says Iran arrested 7,000 people last year in a "shameless campaign of repression".
Those swept up by the crackdown included protesters, students, lawyers, journalists, environmental and women's rights activists, and trade unionists.
Hundreds were sentenced to prison or flogging. At least 26 protesters were killed and nine others died in custody.
The crackdown was a response to unrest over poverty, corruption and the lack of political and social freedoms.
"From underpaid teachers to factory workers struggling to feed their families, those who have dared to demand their rights in Iran today have paid a heavy price," said Philip Luther, Amnesty's Middle East and North Africa director.
Amnesty said at least 112 were arrested or remained in detention during 2018, when women began standing on raised structures in public places and taking off their headscarves to protest against the compulsory hijab law. [BBC] Read more
